Wellhead equipment for suspending multiple tubing strings



July 16, 1963 H. ALLEN ETAL WELLHEAD EQUIPMENT FOR SUSPENDING MULTIPLE TUBING STRINGS Original Filed Oct. 15, 1956 2 Sheets-Sheet l Herder? /4//e/7 Mary/r7 z/arzes lNVENToRs ATTOF/VfVJ July 16, 1963 H. ALLEN ETAL 3,

WELLHEAD EQUIPMENT FOR SUSPENDING MULTIPLE TUBING STRINGS Original Filed Oct. 15, 1956 2 Sheets-Sheet 2 f/err/ /4//e/7 Mary/x7 done:

INVENTORJ BY Y M United States Patent Dfifice 3 097 869 WELLHEAD EQUIPlVIEl WT FOR SUSPENDIN G MULTIPLE TUBING STRINGS Herbert Allen and Marvin R. Jones, Houston, Tex.,

assignors to Cameron Iron Works, Inc., Houston, Tex., a corporation of Texas This invention relates to improved wellhead equipment for suspending a plurality of tubing strings in side-byside relation within a multiple zone well. This application is a division of our copending application, Serial No. 615,976, filed October 15, 1956, and entitled, Wellhead Equipment, now US. Patent No. 2,939,727.

During production from multiple zone wells, the tubing strings are suspended from and sealed OE With respect to a fitting at the wellhead so as to isolate the space about the strings within the well. For this purpose, it has been proposed to seat a bushing Within the bore of the fitting or tubing head subsequent to running drilling and completion tools therethrough, and then run the strings through openings in the bushing having conical seats for supporting similarly shaped hangers on the strings. The hangers are sealed with respect to the bushing and the bushing with respect to the tubing head so as to close the bore and thus seal off the space within the well, as abovementioned.

The principal shortcoming of this earlier equipment is that the openings through the bushing are not large enough to permit the passage of gas lift valves and other auxiliary parts run on the tubing strings. In an application, Serial No. 543,215, filed October 27, 1955 by Herbert Allen, now issued as Patent No. 2,794,505 (which was copending with the aforementioned application, Serial No. 615,976, and assigned to the assignee of the present invention), there is disclosed an assembly in which two hangers of semi-circular shape are seatable on and between pins fixed to the bore of the tubing head for support in side-by-side relation. In this manner upon removal of the hanger-s from the bore, a space is provided through the bore of the tubing head which is substantially as large as the space within the well casing so as to accommodate the passage of such auxiliary parts on the tubing strings.

Unless these pins are 'of only relatively short radial extent, they will interfere with the running of the drilling and completion tools. On the other hand, when the radial extent of the pins is limited for this purpose, the supports they provide for each hanger are so located relative to its weight and the load due to the tubing string suspended therefrom that a moment is induced tending to swing the hanger inwardly of the bore of the tubing into a position interfering with the placement of a hanger adjacent thereto. This problem becomes especially acute in the case of hangers for wells or three or more zones, since such hangers are of correspondingly smaller sector shapes, and particularly less than semi-circular, whereby the moments become greater and the problem of indexing each hanger into place between appropriate pins becomes more complex.

An object of this invention is to provide wellhead equipment having substantially the advantages of the assembly oi the above-mentioned copending application in that hangers are supportable in the bore of a tubing head in a manner to provide, upon their removal therefrom, a space at least substantially no less than the space within the well casing, but in which there is less cause for interference with drilling and completion equipment and wherein the hangers, regardless of size, are more rigidly 3,097,869 Patented July 16,- 1963 supported in proper position within the bore of the tubing head. Thus, the wellhead equipment of the present invention is particularly well adapted for use in suspending three or more tubing strings in side-'by-side relation within a well casing.

Another object is to provide equipment of the character described in the foregoing object in which each of at least all but one of the hangers is seatable and unseatable with respect to the bore of the tubing head independently of the seating and unseating, respectively, of another hanger.

Still another object is to provide equipment of the character described in either of the foregoing objects, in which the hangers are scalable with respect to one another as well as with respect to the bore of the tubing head, when all are seated therein, so as to seal oif the space therethrough.

A further object is to provide equipment of the character described in any one of the foregoing objects in which the hangers are automatically indexed into a predetermined rotative position with respect to the bore of the tubing head as they are seated therein.

Other objects, advantages and features of this invention will be apparent to one skilled in the art upon a consideration of the written specification, the attached claims and the annexed drawings.

In accordance with the present invention, the-re is provided wellhead equipment which includes a tubing head having a bore therethrough and a plurality of sectorshaped hangers supportable within the bore for suspending tubing from the lower ends of openings therethrough. Radially directed and interconnected seating elements are removably seatable across the bore in angularly spaced apart relation, and the hangers are seated in side-by-side relation between adjacent seating elements and the bore. Thus, each space in the bore of the tubing head through which a tubing string must be passed is restricted only by the seating elements upon which the hanger for suspending such string is seatab-le.

This construction accomplishes the more basic objects of the invention since, when the seating elements are disposed across the bore for supporting the hangers, they more rigidly resist any tendency of the hangers to tilt from their supported positions and also provide greater areas of support. On the other hand, when the seating elements are removed from seated position across the bore, they do not interfere with the passage of drilling and completion equipment.

In one embodiment of the invention, the supporting means comprises a spider, the legs of which provide the seating elements, and each hanger is seatable and unseatable with respect to the spider legs independently of the seating and unseating, respectively, of the other hangers. In another embodiment, the seating elements are carried by one hanger so that only the other hangers are independently seatable and unseatable with respect to one another.

In each of the embodiments of the inventiomthe hangers are provided with seal means thereabout for sealing each hanger with respect to adjacent hangers and the tubing head bore so as to seal off the space thereof when all the hangers are seated. More particularly, it is preferred that the seal means about each hanger be directly engageable with the seal means of adjacent hangers and said bore.

In the drawings, wherein like reference characters are used throughout to designate like parts:

FIG. 1 is a perspective view of the first-mentioned embodiment of the present invention, with the tubing head broken away in part and one of the hangers in a position just prior to seating on the legs of the spider;

FIG. 2. is a top plan view of the wellhead equipment of FIG. 1, with all of the hangers in place; and

FIG. 3 is a perspective of the integrated hanger and seating elements of the other embodiment of the invention.

As shown in FIGS. 1 and 2, the first embodiment of the present invention includes a tubing head which is conventionally secured to a casing head (not shown) above the well casing and a plurality of hangers 11 supportable in side-by-side relation within the bore 12 through the tubing head. Tubing strings 13 are secured to the lower ends of longitudinal openings- 14 through said hangers for suspension within the well casing and separate communication with the production zones of the well, in a manner well known in the art.

As is also customary in the art, the tubing head 10 is provided with an annular flange 15 at its upper end for connection during the completion process and subsequent to landing of the hangers 11 with another wellhead member (not'shown), which may be a valve or the like having a bore aligned with the bore 12, by means of bolts 17 (FIG. 2). More particularly, the tubing head is provided with a groove '18 to receive a ring-(type sealing element 20 which is also received in an oppositely facing groove of the other wellhead member so that, when the bolts 17' are tightened up to a desired degree, the tubing head and wellhead member are sealed with respect to one another about the bore 12 through the head.

The upper ends of the openings 14 through the hangers 11 are threaded for connection with handling joints 21 for lowering and raising the hangers with respect to their supported positions in the head. More particularly, each hanger is providedwith an upstanding tubular boss 23 surrounding the opening therethrough, and having a conical outer surface 24 over which a similarly shaped lower end of a corresponding opening in the wellhead member is fittable.

As will be described more fully hereinafter, when the hangers 11 are seated in side-by-side relation within the bore of the tubing head 10, as shown in FIG. 2, they are sealed olf with respect to one another as well as with respect to such tubing head bore. Thus, during production from the several zones through the tubing strings 13, the space within the well casing about said strings and below the hangers is sealed off for use in a manner well known in the ant. Also, with the other wellhead member and additional wellhead equipment connected above the tubing head, suitable control is had over the production from each zone.

Each of the hangers L1 is sector-shaped in cross-section transversely to the opening 1 4 therethrough. More particularly, the outer sides 28 thereof are curved substantially concentrically of the bore of the tubing head and the inner flat sides 29'thereof intersect at approximately the axis of the bore and curved sides. The aggregate of the angles described by the flat sides of the hangers represents a full circle so that, with all the hangers supported in side-by-side relation within the tubing head bore, the space across the bore is at least substantially obstructed. Although in the particular embodiment shown in FIGS. 1 and 2 there are three interchangeably useable hangers each of which describes a sector of substantially 120 degrees, it should be understood that the invention is not limited to such an arrangement. In fact, the concepts of the present invention are broadly applicable to wellhead equipment which includes two or more hangers which need not be alike in cross-section.

The means for supporting the hangers comprises a spider 47 having three legs 49 for extension radially across the bore of the tubing head when the spider is seated therein, as shown in FIG. 1. When the spider is removed, however, the bore 12 of the tubing head is free of any obstructions which might interfere with the passage of drilling and completion equipment. As shown in FIG. 1,

the legs of the spider are arranged to provide spaces therebetween corresponding to the angular relation of the flat sides of the hangers to one another.

The bore of the tubing head is provided with an upwardly facing seat thereabout which comprises a comically tapered bowl 31. Two of the legs 49 of the spider have seating surfaces 48 on their outer ends which are tapered similarly to the bowl 31 for seating thereon in the supported position of the spider. Also, there is a vertically extending slot 50 in the bore of the tubing head which receives an outwardly projecting part 51 on the third leg of the spider so as to automatically index it into a predetermined rotative position as the spider is lowered into the well.

The lower portions of the hangers beneath the fiat sides are recessed inwardly so that each hanger may be separately lowered into tubing supporting position through the appropriate space between the adjacent spider legs and bore of the tubing head. These recessed portions include downwardly and inwardly tapered seating surfaces 52 for seating upon similarly tapered surfaces 53 of the spider legs. Each hanger is also provided with a seating surface beneath its curved side which is tapered correspondingly to the bowl 31' for seatin thereon.

As each hanger is so lowered, its outer seating surface seats upon the bowl 31 and seating surfaces 52 seat upon the seating surfaces 53 of adjacent spider legs so as to support the hanger against movement both downwardly and radially inwardly, as well as against rotational movement. More particularly, each leg of the spider is narrow so that each space between adjacent legs is only slightly smaller than that portion of the tubing hanger supported between said legs which is above the seating surfaces thereof.

Thus, when all the hangers are so supported, as shown in FIG. 2, the flat sides 29 thereof above the seating surfaces 52 are at least closely adjacent the corresponding fiat sides of adjacent hangers, and the outer sides 23 thereof are at least closely adjacent the bore 12 of the tubing head. Thus, sealing members 35, in the form of rings of rubber or other resilient sealing material disposed about all three sides of the hangers, may be energized into sealing engagement with one another as well as with the bore of the tubing head. For this purpose, the tubing head 10 is provided with one or more openings extending radially through the flanges '15 thereof for communication with the seal rings 35. Thus, the rings may be energized into such sealing engagement by means of a plastic material injected under pressure through said openings.

More particularly, the openings 60 are threaded to receive fittings 61 at their outer ends, and connect with the upper ends of slots 62 on the periphery of the seated hangers which connect at their lower ends with the grooves which receive the seal rings. A ball check valve 63 is normally urged by a coil spring 64 into seated engagement with the inner end of a passage 65 through the fitting 61 of each opening, and a plunger 66 is threadedly received within each passage outwardly of said inner end thereof. Thus, upon removal of the plunger, a suitable plastic material may be forced past the check valve 63 for energizing the seal rings. The plunger 66 may then be replaced and used for increasing the pressure on the plastic to a desired degree.

As noted above, the spider legs 49 not only serve to support the hangers but also to locate them in a predetermined rotative position with respect to the tubing head. Thus, upon placement of the wellhead member over the flange 15, the upwardly extending necks 24 of the hangers will automatically align the bolt holes in said member with those in the flange of the tubing head and openings 60' will be properly disposed opposite slots 62. It will also be appreciated that since each of the hangers is seatable and unseatable within the tubing head independently of the seating and unseating, respectively, of any other hanger, the hangers may be lowered into and removed irom tubing suspending position in any desired sequence.

As previously indicated, with the hangers removed from the bore of the tubing head, the spider legs provide the only obstruction across the bore, so that the space therein available for passing the tubing strings and auxiliary parts at least approximately corresponds to the portion of the space within the well casing for accommodating such strings.

The flat sides 29 of the hangers need not necessarily be directly sealable with one another, and the outer curved sides thereof need not necessarily be directly sealable with the bore 112 of the tubing head, when the hangers are supported in side-by-side relation within the tubing head bore. Thus, for example, seal rings about the hangers may be scalable with one or both of the radially extending spider legs and a peripheral seating element intermediate the bore and curved outer sides of the hangers. However, the arrangement shown is preferred as it provides a maximum amount of space through the bore for passing the tubing strings.

Also mounted within the tubing head are a plurality of holddown bolts 41 for preventing movement of the hangers upwardly from their seated positions. These bolts are threadedly received within radial passages in the tubing head for selective movement into or out of engagement within openings (not shown) in the curved side of each of the hangers. As shown in FIG. 1, these bolts are preferably arranged in the upper ends of the tubing head and hangers, respectively. An actuating part 46 on the outer end of each bolt permits rotation thereof within a gland nut 45 for imparting the aforesaid inward and outward movement thereto. Any desired number of bolts, such as the three illustrated in FIG. 2, may be provided for holding each hanger down.

After the well has been drilled so as to penetrate the multiple zones, it may be completed without a loss of pressure within the well. Thus, upon cementing of the casing in place, the tubing head is connected above the casing head and a blowout preventer or like equipment is connected above the tubing head. Packers are then lowered into the well casing and set at levels therein for isolating the production zones from one another in a manner well known in the art of multiple zone well completion.

For example, a first packer may be run and set on the drill pipe between the middle and lowermost of the three production zones. Subsequent packers may then be run on the first string of tubing and set between the middle and uppermost zone and above the uppermost zone, respectively. The lower end of this first string may be received in the first packer for communication with the lowermost zone, and the lower end of each of the other two strings received in one of the remaining packers for communication with the middle and uppermost zones, respectively. Obviously, the spider may be removed during running of the packers on the first string, and then seated across the bore of the tubing head for supporting the hanger 11 for said first string as it is lowered into seated position. Alternatively, it may be possible to run and set all of the packers by wire line, in which case the spider may be seated in supporting position prior to running of any of the strings.

The hangers may be held down in seated position by the bolts 41 and back-pressure valves (not shown) may be lowered into the hangers and connected to the openings 41 therethrough. The blowout preventer may then be removed and replaced by the wellhead member, such as a control valve or suitable flange member, and various other parts connected above said member to complete the wellhead. Upon removal of the back-pressure valves, the zones of the well may be Washed in.

FIG. 3 illustrates part of another embodiment of the invention, and, more particularly, a modified means for supporting hangers 11 within a tubing head 10 of the type shown in FIGS. 1 and 2.. In this form, a hanger is secured between two of three radially extending and angularly spaced apart seating elements '55 so as to support the hanger in tubing suspended position as the supporting means is lowered into the bore of the tubing head 10 and seated upon the bowl 31 thereof. It is obvious from FIG. 3 that the hanger secured to the seating elements 55 occupies the same position, when so supported, as it would if it were separate and seatable between spider legs and the tubing head bore, as in the case of the hanger shown in FIGS. 1 and 2.

Upon seating of the supporting means of FIG. 3, the remaining two hangers may be seated in a manner previously described. Obviously, although each of the latter two hangers is seatable and unseatable independently of the seating and unseating, respectively, of the hanger secured to the seating elements 55, the latter is the first to be seated and last .to be unseated. Thus, it is desirable during completion of a well with this embodiment of the invention, to run and set packers on this first string.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the apparatus.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set north or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

The invention having been described, what is claimed is:

1. Wellhead equipment, comprising a tubing head having a vertical bore therethrough and an annular upwardly disposed seat within the bore, supporting means seated on said seat, a plurality of tubing hangers engaging the wall of said bore, said supporting means adapted to be lowered through the bore and landed on said seat to bridge the bore and align said hangers in side-by-side relation within the bore, at least one of said tubing hangers having means for seating on a portion of the wall of the tubing head bore and on said supporting means.

2. Wellhead equipment of the character defined in claim 1, wherein one hanger is fixedly secured to and lowerable with the supporting means.

3. Wellhead equipment, comprising a tubing head having a vertical bore therethrough, said bore having an up- Wardly disposed seat therein, a plurality of tubing hangers each engaging and being at least partially supported by said seat a support member in said bore and lowerable therethrough for landing in a circumfierentially oriented position within the bore on said seat and having means for supporting said tubing hangers in side-by-side relation within the bore when the member is so landed, said supporting means including legs which extend substantially radially across the bore to define at least one opening between them and the bore for receiving a tubing hanger therein, upwardly facing seats on said legs and the upwardly disposed seat on the bore defining said one opening, the tubing hanger to be received within the one opening having downwardly facing seats thereon for landing on the seats on the supporting means legs and bore.

4. Wellhead equipment of the character defined in claim 3, wherein the seats on said supporting member legs and bore of the tubing head define openings in the bore for receiving each of said tubing hangers, and each said hanger has downwardly facing seats thereon for landing on the seats on the supporting member legs and bore which define the particular opening in which said hanger is to be received.

5. Wellhead equipment of 1 the character defined in claim 3, wherein one-tubing hanger is fixedly secured to and lowerable with the supporting member.

6. Wellhead equipment of the character defined in claim 5, wherein the seats on said supporting member legs and bore of the tubing head define openings in the bore for receiving each of said tubing hangers in addition to said one, and each of said additional hangers has downwardly facing seats on the supporting member legs and bore' which define the particular opening in which said hanger is to' be received.

7. Wellhead equipment of the character defined in claim 3, wherein each of the seats on the supporting member-legs and bore taper downwardly and inwardly, and the seats on the tubing hanger for landing thereon are correspondingly tapered.

8. Wellhead equipment, comprising a tubing head having a vertical bore therethrough and an upwardly directed seat therein, a vertically removable tubing hanger supporting member on the seat-within the bore, aplurality of tubing hangers in the bore supported on said member and said seat, said supporting member supporting said hangers in side-by-side relation within the bore and including interconnected, angularly spaced-apart legs which extend radially across the bore to define at least one seetor-shaped opening between them and the bore for re-- ceiving a tubing hanger therein, upwardly facing seats on said legs adjacent said opening, and an upwardly facing arcuate seat on' the bore intermediate the intersection named tubing hanger to be received within the one open ing being sector-shaped and having downwardly facing seats adjacent its side edges as well as across its arcuateside for landing on the seats on the supporting member and bore which-define said one opening.

9. Wellhead equipment, comprising a tubing head having a vertical bore therethrough andia downwardly and inwardly tapered bowl in the bore, a spider in said bore having aplurality of angularly spaced-apart legs lowerable through the bore to land upon the bowl with said legs extending radially across the bore to define at least one sector-shaped opening between them and the bowl in the bore, a plurality of tubing hangers in said bore engaging said spider and said seat, and means on the spider for supporting said tubing hangers in side-by-side relation within the bore, including upwardly facing seats adjacent the side edges of the legs of the spider, the tubing hanger to be received within the. one sector-shaped opening having the so received portion thereof sectorshaped and having downwardly facing seats adjacent its side edges for seating on the spider leg seats and a downwardly and inwardly tapering seat on its arcuate side for landingon the bowl in the bore.

References Cited in the file of this patent UNITED STATES PATENTS 449,169 OBrien Mar. 31, 1891 780,861 Buzard Jan. 24, 1905 1,774,196 Davis Aug. 26, 1930 2,794,505 Allen June 4, 1957 2,830,665 Burns et a1. Apr. 15, 1958 2,939,727 Allen June 7, 1960 3,001,803 Watts Sept. 26, 1961 

1. WELLHEAD EQUIPMENT, COMPRISING A TUBING HEAD HAVING A VERTICAL BORE THERETHROUGH AND AN ANNULAR UPWARDLY DISPOSED SEAT WITHIN THE BORE, SUPPORTING MEANS SEATED ON SAID SEAT, A PLURALITY OF TUBING HANGERS ENGAGING THE WALL OF SAID BORE, SAID SUPPORTING MEANS ADAPTED TO BE LOWERED THROUGH THE BORE AND LANDED ON SAID SEAT TO BRIDGE THE BORE AND ALIGN SAID HANGERS IN SIDE-BY-SIDE RELATION WITHIN THE BORE, AT LEAST ONE OF SAID TUBING HANGERS HAVING MEANS FOR SEATING ON A PORTION OF THE WALL OF THE TUBING HEAD BORE AND ON SAID SUPPORTING MEANS. 